Is it healthy For a Building to Have a 100% Air Tight Seal?

No. While having a 100% air tight seal is essential to stopping heat loss and reducing energy bills, occupants need fresh air. As such, buildings sealed with Spray Foam must have a heat recovery air exchanger installed. In the winter, this simple machine brings cold fresh air from the outside and passes it by (without mixing) the warm stale air being expelled. This allows the fresh air to pick up the heat from the stale air, maintaining energy efficiency while providing a continuous supply of fresh air. In the summer, the opposite occurs giving the same results.